Socioeconomic disparities in incidents at toxic sites during Hurricane Harvey

Background: Hurricane Harvey facilitated exposure to various toxic substances and floodwater throughout the greater Houston metropolitan area. Although disparities exist in this exposure and vulnerable populations can bear a disproportionate impact, no research has integrated disparities in exposure to toxic incidents following Hurricane Harvey. Objective: The objective of this study was to analyze the relationship between flooding, socioeconomic status (SES), and toxic site incidents. Methods: Data on toxic site locations, reported releases, and flood water depths during Hurricane Harvey in the greater Houston area were compiled from multiple sources. A multivariable logistic regression was performed to predict the odds of a toxic site release by flooding at the site, SES and racial composition of the census tract. Results: 83 out of 1403 toxic sites (5.9%) had reported releases during Hurricane Harvey. The proportion of toxic sites with reported incidents across increasing SES index quintiles were 8.35, 7.67, 5.14, 4.55, and 0.51, respectively. The odds of an incident were lower in the highest SES quintile areas (OR_adj = 0.06, 95% CI: 0.01–0.42) compared to the lowest SES quintile. Flooding was similar at toxic sites with and without incidents, and was distributed similarly and highest at toxic sites located in lower SES quintiles. Significance: Despite similar flooding across toxic sites during Hurricane Harvey, areas with lower SES were more likely to have a toxic release during the storm, after accounting for number of toxic sites. Improving quality of maintenance, safety protocols, number of storm-resilient facilities may minimize this disproportionate exposure and its subsequent adverse outcomes among socioeconomically vulnerable populations.